Which parameter directly describes water opacity due to suspended solids?

Which parameter directly describes water opacity due to suspended solids?

• A. Turbidity
• B. Dissolved Oxygen
• C. Temperature
• D. Alkalinity

Answer: (A)

Turbidity is the parameter that directly describes how opaque water is because of suspended solids. When particles like silt, clay, or organic debris are floating in the water, they scatter and absorb light, making the water look cloudy and reducing light transmission. Turbidity quantifies that cloudiness, typically in units like NTU or FNU, and serves as a practical indicator of the amount of material in suspension. Dissolved Oxygen measures how much oxygen is dissolved in the water, which relates to aquatic life and chemical processes rather than cloudiness. Temperature affects the water’s physical and chemical behavior but not how much light is blocked by particles. Alkalinity refers to the water’s buffering capacity against pH changes, not to the presence of suspended solids. So turbidity best captures the concept of opacity caused by suspended solids, linking the visible cloudiness to the actual suspended material in the water.

Turbidity is the parameter that directly describes how opaque water is because of suspended solids. When particles like silt, clay, or organic debris are floating in the water, they scatter and absorb light, making the water look cloudy and reducing light transmission. Turbidity quantifies that cloudiness, typically in units like NTU or FNU, and serves as a practical indicator of the amount of material in suspension. Dissolved Oxygen measures how much oxygen is dissolved in the water, which relates to aquatic life and chemical processes rather than cloudiness. Temperature affects the water’s physical and chemical behavior but not how much light is blocked by particles. Alkalinity refers to the water’s buffering capacity against pH changes, not to the presence of suspended solids. So turbidity best captures the concept of opacity caused by suspended solids, linking the visible cloudiness to the actual suspended material in the water.